Display apparatus and method of manufacturing the same

ABSTRACT

A display apparatus includes: a substrate; a pixel electrode above the substrate; a first low reflection layer spaced apart from the pixel electrode at a same layer as the pixel electrode and comprising a lower layer having conductivity and an upper layer above the lower layer; a pixel-defining layer above the first low reflection layer and having an opening exposing at least a part of the pixel electrode; an intermediate layer above the pixel electrode and comprising an organic emission layer; and an opposite electrode above the intermediate layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2016-0085071, filed on Jul. 5, 2016, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND 1. Field

One or more example embodiments relate to a display apparatus and amethod of manufacturing the display apparatus.

2. Description of the Related Art

A display apparatus for displaying images is manufactured over an arraysubstrate on which patterns are formed, the patterns including thin filmtransistors (TFTs), capacitors, and wires connecting the TFTs and thecapacitors.

The display apparatus is used in various environments. When the displayapparatus is used outdoors or bright indoors, a contrast ratio of animage is reduced due to external light reflected from metals includingwires and electrodes that are included in the display apparatus, whichcauses deterioration in visibility.

To prevent the reflection of the external light, the display apparatusincludes various types of anti-reflectors.

SUMMARY

A display apparatus according to the related art includesanti-reflectors such as a black matrix, a color filter, and/or acircular polarizer. However, the display apparatus according to therelated art includes separate layers to prevent reflection, which causesan increase in the number of processes, an increase in a thicknessthereof, and an occurrence of a color shift according to a viewingangle.

To solve several problems including the aforementioned problem, thepresent disclosure provides a display apparatus including a lowreflection layer without a separate mask process, thereby reducing thenumber of processes, a thickness thereof, and occurrence of a colorshift according to a viewing angle, and a method of manufacturing thedisplay apparatus.

Additional aspects will be set forth in part in the description thatfollows and, in part, will be apparent from the description, or may belearned by practice of the presented example embodiments.

According to one or more example embodiments, a display apparatusincludes: a substrate; a pixel electrode above the substrate; a firstlow reflection layer spaced apart from the pixel electrode at a samelayer as the pixel electrode and including a lower layer havingconductivity and an upper layer above the lower layer; a pixel-defininglayer above the first low reflection layer and having an openingexposing at least a part of the pixel electrode; an intermediate layerabove the pixel electrode and including an organic emission layer; andan opposite electrode above the intermediate layer.

A height of the first low reflection layer may be greater than a heightof the pixel electrode.

The upper layer of the first low reflection layer may include aplurality of layers having different refractive indexes.

Light reflected from a boundary surface between the pixel-defining layerand an uppermost layer among the plurality of layers and light reflectedfrom a boundary surface between the plurality of layers maydestructively interfere with each other.

The reflectance of the upper layer of the first low reflection layer maybe less than about 6%.

The display apparatus may further include: a low reflection etchinglayer between the pixel-defining layer and an edge of the pixelelectrode, wherein the pixel-defining layer covers the edge of the pixelelectrode.

The upper layer of the first low reflection layer may include a stackstructure of aluminum (Al)/aluminum oxide (AlO_(x))/titanium (Ti), astack structure of aluminum (Al)/titanium (Ti)/indium zinc oxide(IZO)/titanium (Ti), or a stack structure of copper (Cu)/indium tinoxide (ITO)/copper oxide (Cu₂O).

The first low reflection layer may be electrically grounded.

The display apparatus may further include: a thin film encapsulationlayer above the opposite electrode and including at least one inorganiclayer and at least one organic layer; and a touch panel above the thinfilm encapsulation layer.

The touch panel may include: a detection electrode detecting a touchsignal and including a plurality of conductive lines in a grid shape; asecond low reflection layer spaced apart from the detection electrode ata same layer as the detection electrode and surrounding the pixelelectrode; a bridge overlapping a part of the detection electrode on aplane, including a plurality of conductive lines in a grid shape, andelectrically connected to the detection electrode; and an insulatinglayer between the bridge and the detection electrode and having anopening through which the bridge and the detection electrode areelectrically connected to each other.

Widths of the plurality of conductive lines included in the detectionelectrode may be less than widths of the plurality of conductive linesincluded in the bridge.

The detection electrode and the second low reflection layer may includea plurality of layers having refractive indexes, wherein lightsreflected from boundary surfaces of the plurality of layersdestructively interfere with each other.

The detection electrode and the second low reflection layer may includea stack structure of aluminum (Al)/aluminum oxide (AlO_(x))/titanium(Ti), a stack structure of aluminum (Al)/titanium (Ti)/indium zinc oxide(IZO)/titanium (Ti), or a stack structure of copper (Cu)/indium tinoxide (ITO)/copper oxide (Cu₂O).

The bridge may include a plurality of layers having refractive indexes,wherein lights reflected from boundary surfaces of the plurality oflayers may destructively interfere with each other.

According to one or more example embodiments, a method of manufacturinga display apparatus includes: sequentially forming a conductive layerand a low reflection layer above a substrate; forming a first lowreflection layer including a lower layer having conductivity and anupper layer above the lower layer, a pixel electrode, and a lowreflection etching layer above the pixel electrode by patterning theconductive layer and the low reflection layer; forming a pixel-defininglayer above the first low reflection layer and having an openingexposing at least a part of the low reflection etching layer; exposingthe pixel electrode by etching at least a part of the low reflectionetching layer by using the pixel-defining layer as a mask; forming anintermediate layer above the exposed pixel electrode, the intermediatelayer including an organic emission layer; and forming an oppositeelectrode above the intermediate layer.

The forming of the low reflection layer may include sequentiallystacking a plurality of layers having different refractive indexes.

The upper layer of the first low reflection layer may include a stackstructure of aluminum (Al)/aluminum oxide (AlO_(x))/titanium (Ti), astack structure of aluminum (Al)/titanium (Ti)/indium zinc oxide(IZO)/titanium (Ti), or a stack structure of copper (Cu)/indium tinoxide (ITO)/copper oxide (Cu₂O).

The method may further include: after the forming of the oppositeelectrode, forming a thin film encapsulation layer above the oppositeelectrode, the thin film encapsulation layer including at least oneinorganic layer and at least one organic layer; and forming a touchpanel above the thin film encapsulation layer.

The forming of the touch panel may include: forming a detectionelectrode detecting a touch signal and including a plurality ofconductive lines in a grid shape, and a second low reflection layersurrounding the pixel electrode; forming an insulating layer having anopening exposing a part of the detection electrode above the detectionelectrode and the second low reflection layer; and forming a bridgeincluding a plurality of conductive lines in a grid shape, covering theopening of the insulating layer, and electrically connected to thedetection electrode above the insulating layer.

The forming of the detection electrode and the second low reflectionlayer may include sequentially stacking a plurality of layers havingdifferent refractive indexes, wherein lights reflected from boundarysurfaces of the plurality of layers destructively interfere with eachother.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the example embodiments,taken in conjunction with the accompanying drawings in which:

FIG. 1 is schematic plan view of a display apparatus, according to anexample embodiment;

FIG. 2 is a cross-sectional view taken along a line II-II′ of FIG. 1;

FIGS. 3 and 4 are respectively cross-sectional views of a first lowreflection layer of FIG. 2, according to an example embodiment;

FIG. 5 is a plan view of a detection electrode and a bridge of a partialarea of a display apparatus, according to an example embodiment;

FIG. 6 is an enlarged plan view of region A of FIG. 5;

FIG. 7 is a plan view of a detection electrode and a second lowreflection layer that are included in FIG. 6;

FIG. 8 is a cross-sectional view taken along a line VIII-VIII′ of FIG.6;

FIG. 9 is a plan view of a display apparatus, according to anotherexample embodiment;

FIG. 10 is a cross-sectional view taken along a line X-X′ of FIG. 9;

FIGS. 11A, 11B, 11C, 11D, 11E and 11F are cross-sectional views forsequentially describing a method of manufacturing the display apparatus,according to an example embodiment; and

FIGS. 12A, 12B and 12C are cross-sectional views for describing anoperation of forming a touch panel in an upper area of a thin filmencapsulation layer in a method of manufacturing the display apparatus,according to another example embodiment.

DETAILED DESCRIPTION

As the disclosure allows for various changes and numerous exampleembodiments, particular example embodiments will be illustrated in thedrawings and described in detail in the written description. Effects andfeatures of the disclosure and methods of accomplishing the same may beunderstood more readily by referencing the following detaileddescription of preferred example embodiments and the accompanyingdrawings. The disclosure may, however, be embodied in many differentforms and should not be construed as being limited to the exampleembodiments set forth herein. As used herein, the term “and/or” includesany and all combinations of one or more of the associated listed items.Expressions such as “at least one of,” when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list.

Reference will now be made in detail to example embodiments, which areillustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout, and redundant descriptionsthereof are not provided here.

While terms such as “first,” “second,” etc., may be used to describevarious components, such components are not limited to the above terms.The above terms are used only to distinguish one component from another.

Throughout the specification, an expression used in the singularencompasses the expression of the plural, unless it has a clearlydifferent meaning in the context.

Throughout the specification, it is to be understood that the terms suchas “including” or “having,” etc., are intended to indicate the existenceof the features or components disclosed in the specification, and arenot intended to preclude the possibility that one or more other featuresor components may exist or may be added.

In the drawings, for convenience of description, the thicknesses ofelements may be exaggerated for clarity. For example, the thicknessesand sizes of elements in the drawings are arbitrarily shown forconvenience of description; thus, the spirit and scope of the presentdisclosure are not necessarily defined by the drawings.

FIG. 1 is schematic plan view of a display apparatus, according to anexample embodiment. FIG. 2 is a cross-sectional view taken along a lineII-II′ of FIG. 1.

Referring to FIGS. 1 and 2, the display apparatus according to anexample embodiment may include a substrate 10, a pixel electrode 20above the substrate 10, a lower layer 31 spaced apart from the pixelelectrode 20 at the same layer and having conductivity, a first lowreflection layer 30 including an upper layer 32 above the lower layer31, a pixel-defining layer 40 above the first low reflection layer 30and having an opening 40H exposing at least a part of the pixelelectrode 20, an intermediate layer 50 above the pixel electrode 20 andincluding an emission layer, and an opposite layer 60 above theintermediate layer 50.

The substrate 10 may include a display area on which an image isimplemented and a peripheral area outside the display area and mayinclude various materials such as a glass material, a metal material, ora plastic material.

A buffer layer (not shown) may be above the substrate 10, the bufferlayer including inorganic materials such as silicon oxide, siliconnitride, and/or silicon oxynitride. The buffer layer (not shown) mayincrease flatness of an upper surface of the substrate 10 or may preventor minimize penetration of impurities from the substrate 10 into anactive layer of a thin film transistor TFT. The buffer layer (not shown)may be omitted according to circumstances.

The thin film transistor TFT may be above the substrate 10 to controlwhether each of a plurality of pixels emits light. The thin filmtransistor TFT may include an active layer ACT, a gate electrode GATinsulated from the active layer ACT, and a source electrode SE and adrain electrode DE that are electrically connected to the active layerACT, the active layer ACT including a semiconductor material such asamorphous silicon, polysilicon, an oxide semiconductor, or an organicsemiconductor material.

A via insulating layer 12 may be above the thin film transistor TFT andcover the thin film transistor TFT. The via insulating layer 12 may havea flat upper surface on which the pixel electrode 20 may be formed flat.The via insulating layer 12 may include an organic material such asacryl, benzocyclobutene (BCB), polyimide (PI), or hexamethyldisiloxane(HMDSO).

The pixel electrode 20 may be above the via insulating layer 12 and maybe electrically connected to the thin film transistor TFT. The pixelelectrode 20 may be arranged in each pixel in an island shape. The lowerlayer 31 of the first low reflection layer 30 may be at the same layeras the pixel electrode 20. The lower layer 31 may have conductivity. Thelower layer 31 may include the same material as the pixel electrode 20.Referring to FIG. 1, the lower layer 31 may have a mesh shape on aplane.

The pixel electrode 20 and the lower layer 31 may include a lightreflection material and may include a reflection layer including silver(Ag), magnesium (Mg), aluminum (Al), platinum (Pt), gold (Au), nickel(Ni), neodymium (Nd), iridium (Ir), chromium (Cr), and combinationsthereof and a transparent conductive layer arranged in an upper portionand/or a lower portion of the reflection layer. The transparentconductive layer may include at least one selected from the groupconsisting of ITO, IZO, ZnO, In₂O₃, IGO, and AZO. However, the presentdisclosure is not limited thereto. The pixel electrode 20 and the lowerlayer 31 may include various materials and may have a single-layerstructure or a multilayer structure.

The upper layer 32 may be above the lower layer 31. The lower layer 31and the upper layer 32 may constitute the first low reflection layer 30.The first low reflection layer 30 may reduce an external lightreflectance of the display apparatus. The first low reflection layer 30may perform a low reflection function by stacking a plurality ofmaterial layers having different refractive indexes and allowing lightreflected from each interface to be offset and destructively interfere.This will be described later. The first low reflection layer 30 may havelow reflectance to show a black color. According to another exampleembodiment, the upper layer 32 of the first low reflection layer 30 maybe only above the lower layer 31 and may not be above the pixelelectrode 20.

According to an embodiment, a height of the first low reflection layer30 may be greater than a height h₄ of the pixel electrode 20. Referringto FIG. 2, the lower layer 31 may have a height h₁. The upper layer 32having a height h₂ may be above the lower layer 31. In this regard, asum of the heights of the lower layer 31 and the upper layer 32, i.e., aheight h₃=(h₁+h₂) of the first low reflection layer 30, may be greaterthan a height h₄ of the pixel electrode 20. As will be described later,the lower layer 31 and the pixel electrode 20 may be formed by the sameprocess, and thus the height h₄ of the pixel electrode 20 may besubstantially the same as the height h₁ of the lower layer 31. As willbe described later, the upper layer 32 and a low reflection etchinglayer 32E may be formed by the same process, and thus a height h₅ of thelow reflection etching layer 32E above an edge of the pixel electrode 20may be substantially the same as the height h₂ of the upper layer 32.

The pixel-defining layer 40 may be above the first low reflection layer30 and may have an opening 40H exposing at least a part of the pixelelectrode 20. The pixel-defining layer 40 may include an organicmaterial such as PI or HMDSO but is not limited thereto. Thepixel-defining layer 40 may have a single layer structure or amultilayer structure. The pixel-defining layer 40 may define a pixelarea PA. For example, the pixel area PA may be defined as an areaexposing the pixel electrode 20 by the opening 40H of the pixel-defininglayer 40.

The intermediate layer 50 may be above the pixel electrode 20 exposed bythe pixel-defining layer 40 and may include at least one common layerand an organic emission layer. The organic emission layer may includevarious organic materials including copper phthalocyanine (CuPc),N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB),tris-8-hydroxyquinoline alum inum)(Alq3), and the like.

The opposite electrode 60 may be above the intermediate layer 50. Theopposite electrode 60 may be formed as one body over a plurality ofpixels, unlike the pixel electrode 20. If a gate-ON signal is applied tothe thin film transistor TFT, a voltage difference may occur between thepixel electrode 20 and the opposite electrode 60, and thus electrons andholes may meet in the organic emission layer of the intermediate layer50 and generate light. The opposite electrode 60 may be a translucentelectrode and may include metal having a thin film shape having athickness of several nanometers to several tens of nanometers to allowlight to pass through. For example, the opposite electrode 60 mayinclude Ag, Al, Mg, Li, Ca, Cu, LiF/Ca, LiF/Al, MgAg, or CaAg. However,a structure and material of the opposite electrode 60 are not limitedthereto and may vary.

The display apparatus according to an embodiment may be a top-emissiontype display apparatus in which light emitted from the organic emissionlayer passes through the opposite electrode 60 to the outside of thedisplay apparatus.

FIGS. 3 and 4 are respectively cross-sectional views of the first lowreflection layer 30 of FIG. 2.

According to an embodiment, the upper layer 32 of the first lowreflection layer 30 may include a plurality of layers having differentrefractive indexes. Light reflected from a boundary surface between thepixel-defining layer 40 and an uppermost layer among the plurality oflayers and light reflected from a boundary surface between the pluralityof layers may destructively interfere with each other.

Referring to FIG. 3, the upper layer 32 of the first low reflectionlayer 30 may include, for example, two layers 32A and 32B havingdifferent refractive indexes. Supposing that a path of light reflectedfrom a boundary surface of the pixel-defining layer 40 and the top layer32B of the upper layer 32 is P1, a path of light reflected from aboundary surface of the top layer 32B and the bottom layer 32A of theupper layer 32 is P2, and a path of light reflected from a boundarysurface of the upper layer 32 and the lower layer 31 is P3, refractiveindexes and thicknesses of the layers 32A and 32B included in the upperlayer 32 may be adjusted, thereby allowing light due to path differencesof P1, P2, and P3 to be offset from each other. That is, reflectance oflight incident from outside of a display apparatus may be reduced by theupper layer 32 above the lower layer 31. In this case, the upper layer32 may show a black color.

Referring to FIG. 4, refractive indexes and thicknesses of layersincluded in the upper layer 32 and the lower layer 31 may be adjusted,and thus the upper layer 32 and the lower layer 31 may show a blackcolor as a whole. For example, the lower layer 31 arranged at the samelayer as the pixel electrode 20 may include two layers 31A and 31B.

In this regard, supposing that the path of the light incident fromoutside of the display apparatus and reflected from the boundary surfaceof the pixel-defining layer 40 and the top layer 32B of the upper layer32 is P1, the path of the light reflected from the boundary surface ofthe top layer 32B and the bottom layer 32A of the upper layer 32 is P2,the path of the light reflected from the boundary surface of the upperlayer 32 and the lower layer 31 is P3, a path of light reflected from aboundary surface of the top layer 31B and the bottom layer 31A of thelower layer 31 is P4, and a path of light reflected from the bottomlayer 31A of the lower layer 31 and the via insulating layer 12 is P5,refractive indexes and thicknesses of the layers 31A, 31B, 32A, and 32Bincluded in the lower layer 31 and the upper layer 32 may be adjusted,thereby generating maximum destructive interference of light due to pathdifferences of P1, P2, P3, P4, and P5. That is, reflectance of externallight may be reduced by the lower layer 31 and the upper layer 32. Inthis case, the first low reflection layer 30 may show a black color as awhole. In this case, refractive indexes and thicknesses of all thelayers 31A, 31B, 32A, and 32B included in the lower layer 31 and theupper layer 32 may be adjusted, and thus reflectance of the first lowreflection layer 30 may be reduced as a whole. Thus, if only the lowerlayer 31 is separately arranged, the lower layer 31 may not show a blackcolor. Therefore, the pixel electrode 20 including the same material asthe lower layer 31 at the same layer as the lower layer 31 may not showthe black color.

According to an embodiment, reflectance of the upper layer 32 of thefirst low reflection layer 30 may be equal to or less than about 6%.Reflectance means a ratio of intensity of reflection light with respectto incidence light, and thus the reflectance of the upper layer 32 maybe equal to or greater than 0%.

The display apparatus according to an example embodiment may furtherinclude a low reflection etching layer 32E between the pixel-defininglayer 40 and an edge of the pixel electrode 20, wherein thepixel-defining layer 40 covers the edge of the pixel electrode 20. Thiswill be described later in connection with a method of manufacturing thedisplay apparatus.

According to an embodiment, the upper layer 32 of the first lowreflection layer 30 may include a stack structure of aluminum(Al)/aluminum oxide (AlO_(x))/titanium (Ti), a stack structure ofaluminum (Al)/titanium (Ti)/indium zinc oxide (IZO)/titanium (Ti), or astack structure of copper (Cu)/indium tin oxide (ITO)/copper oxide(Cu₂O).

According to an embodiment, the first low reflection layer 30 may beelectrically grounded. When the first low reflection layer 30 iselectrically grounded, abnormal driving characteristics of the displayapparatus may be prevented.

The display apparatus including the first low reflection layer 30 maynot need a black matrix layer and/or a circular polarizer in a non-pixelarea to prevent reflection of external light, and thus a thickness ofthe display apparatus may be reduced. Thus, a folding characteristic ofthe display apparatus may be enhanced. A white angular dependency (WAD),in which a color of white light changes due to a color shift accordingto a viewing angle, may also be reduced.

A display apparatus further including a thin film encapsulation layer 70and a touch panel TP will be described below.

FIG. 5 is a plan view of a detection electrode 80 and a bridge 84 of apartial area of a display apparatus, according to an example embodiment.FIG. 6 is an enlarged plan view of region A of FIG. 5. FIG. 7 is a planview of the detection electrode 80 and a second low reflection layer 83that are included in FIG. 6. FIG. 8 is a cross-sectional view takenalong a line VIII-VIII′ of FIG. 6.

The display apparatus according to an example embodiment may furtherinclude the thin film encapsulation layer 70 above the oppositeelectrode 60 at least one inorganic layer and the touch panel T abovethe thin film encapsulation layer 70, the thin film encapsulation layer70 including at least one inorganic layer, for example, inorganic layers71 and 73, and at least one organic layer 72.

The display apparatus according to an example embodiment may furtherinclude the touch panel TP for detecting a touch of a user. The touchpanel TP may include the detection electrode 80 detecting a touch signaland including a plurality of conductive lines in a grid shape, thesecond low reflection layer 83 spaced apart from the detection electrode80 at the same layer and surrounding the pixel electrode 20, the bridge84 overlapping a part of the detection electrode 80 on a plane,including a plurality of conductive lines in a grid shape, andelectrically connected to the detection electrode 80, and an insulatinglayer 90 between the bridge 84 and the detection electrode 80 and havingan opening 90H through which the bridge 84 and the detection electrode80 are electrically connected to each other.

Referring to FIG. 5, the detection electrode 80 may include a pluralityof first detection electrodes 81 and a plurality of second detectionelectrodes 82, which cross each other. The plurality of first detectionelectrodes 81 may be formed long in a first direction D1 and may bealigned in a second direction D2 crossing the first direction D1. Theplurality of second detection electrodes 82 may be formed long in thesecond direction D2 and may be aligned in the first direction D1.

The second detection electrodes 82 may be connected to each other on aplane, whereas the first detection electrodes 81 may be physicallyseparated from each other. However, the first detection electrodes 81may be electrically connected by the bridge 84 arranged in a differentlayer.

The insulating layer 90 may be between the bridge 84 and the detectionelectrode 80. The insulating layer 90 may be between the seconddetection electrodes 82 and the bridge 84 to insulate the seconddetection electrodes 82 and the bridge 84 from each other. The opening90H of the insulating layer 90 may be formed in a part of an area inwhich the bridge 84 and the first detection electrode 81 overlap suchthat the first detection electrodes 81 are buried in the opening 90H andare electrically connected to the bridge 84.

If a human's finger or an object such as a stylus pen contacts thedisplay apparatus including the above-described detection electrode 80,a capacitance change due to a contact location may be provided to adriving circuit side from the first and second detection electrodes 81and 82 via outside wirings (not shown) and pads (not shown) that areconnected to the first and second detection electrodes 81 and 82. Next,the capacitance change may be converted into an electrical signal by Xand Y input processing circuits (not shown), and thus the contactlocation may be obtained.

The detection electrode 80 and the bridge 84 may have a structure inwhich the plurality of conductive lines cross in the grid shape. Thatis, the detection electrode 80 and the bridge 84 may have a metal meshpattern in a net shape. In this regard, an alignment shape of theconductive lines is not limited to an orthogonal shape. The conductivelines may diagonally cross each other or may be linearly bent.

A dummy electrode 85 may be arranged in a space between the firstdetection electrodes 81 and the second detection electrodes 82. Thedummy electrode 85 may also have a metal mesh pattern in a net shapelike the detection electrode 80. The detection electrode 80 and thedummy electrode 85 may be physically separated from each other. That is,dense metal meshes of FIG. 5 may not be physically connected to eachother but may be disconnected from each other between boundaries of thefirst detection electrodes 81 and the second detection electrodes 82.Thus, the detection electrode 80 and the dummy electrode 85 may beelectrically insulated from each other. The dummy electrode 85 mayreduce reflectance of external light in an area overlapping the dummyelectrode 85 on a plane.

FIG. 6 is an enlarged plan view of region A of FIG. 5. FIG. 7 is a planview of the detection electrode 80 and the second low reflection layer83 that are included in FIG. 6.

Referring to FIG. 7, each of the conductive lines of the detectionelectrode 80 arranged in the grid shape or the net shape may have afirst width w₁ and may be arranged in a location overlapping thepixel-defining layer 40. The conductive lines of the detection electrode80 may not overlap the pixel area PA.

The second low reflection layer 83 may be arranged at the same layer asthe detection electrode 80 to surround the pixel area PA. That is, thesecond low reflection layer 83 may surround the pixel electrode 20 on aplane and may overlap an area covered by the pixel-defining layer 40 ofthe pixel electrode 20 on a plane. In this regard, the second lowreflection layer 83 may have a rectangular frame shape and may beinsulated from the detection electrode 80. The plurality of second lowreflection layers 83 respectively surrounding the pixel areas PA may becompletely separated from each other.

The bridge 84 may be above the detection electrode 80 and the second lowreflection layer 83. Referring to FIG. 6, each of the conductive linesof the bridge 84 may have a second width w₂ and may be arranged in alocation overlapping the pixel-defining layer 40. Each of the conductivelines of the detection electrode 80 may not overlap the pixel area PA.

According to an embodiment, the first width w₁ of each of the conductivelines included in the detection electrode 80 may be less than the secondwidth w₂ of each of the conductive lines included in the bridge 84.Referring to FIGS. 6 and 8, since the width w₂ of each of the conductivelines included in the bridge 84 is greater than the width w₁ of each ofthe conductive lines included in the detection electrode 80, theconductive lines of the detection electrode 80 overlapping the bridge 84may not be exposed but may be hidden when viewed from above. Theconductive lines may hide a trench 80T that is an empty space betweeneach of the conductive lines of the detection electrode 80 and thesecond low reflection layer 83. That is, the width w₂ of each of theconductive lines included in the bridge 84 may be greater than a sumw₁+2w₃ of the first width w₁ of each of the conductive lines included inthe detection electrode 80 and a third width w₃ of each of the bothtrenches 80T. In this case, the trench 80T overlapping the bridge 84 maynot be exposed but may be hidden when viewed from the front.

Referring to FIG. 8, the thin film encapsulation layer 70 may be abovethe opposite electrode 60 and may include the at least one inorganiclayer 71 and 73 and the at least one organic layer 72. The thin filmencapsulation layer 70 may prevent or reduce penetration of moisture oroxygen from outside into a display area including the plurality of pixelareas PA of the display apparatus.

The detection electrode 80 and the second low reflection layer 83 may bearranged at the same layer above the thin film encapsulation layer 70.The insulating layer 90 may be above the second low reflection layer 83.In this regard, the insulating layer 90 may have the opening 90H in aportion where the bridge 84 and the detection electrode 80 areconnected. The bridge 84 may fill the opening 90H of the insulatinglayer 90 to connect, for example, the first detection electrodes 81 thatare adjacent to each other.

According to an embodiment, the detection electrode 80 and the secondlow reflection layer 83 may include a plurality of layers havingdifferent refractive indexes. Lights reflected from interfaces of theplurality of layers may destructively interfere with each other. In thisregard, the detection electrode 80 and the second low reflection layer83 may include a same layer.

Similarly to the first low reflection layer 30 described with referenceto FIGS. 3 and 4, refractive indexes and thicknesses of the layersincluded in the detection electrode 80 and the second low reflectionlayer 83 may be adjusted, thereby generating maximum destructiveinterference of the light reflected from interfaces of the plurality oflayers included in the second low reflection layer 83 due to pathdifferences. That is, reflectance of external light may be reduced bythe second low reflection layer 83. In this case, the detectionelectrode 80 and the second low reflection layer 83 may show a blackcolor.

According to an embodiment, the detection electrode 80 and the secondlow reflection layer 83 may include a stack structure of aluminum(Al)/aluminum oxide (AlO_(x))/titanium (Ti), a stack structure ofaluminum (Al)/titanium (Ti)/indium zinc oxide (IZO)/titanium (Ti), or astack structure of copper (Cu)/indium tin oxide (ITO)/copper oxide(Cu₂O).

According to an embodiment, the bridge 84 may include a plurality oflayers having different refractive indexes. Lights reflected frominterfaces of the plurality of layers may destructively interfere witheach other.

In this regard, the bridge 84 may also include a stack structure ofaluminum (Al)/aluminum oxide (AlO_(x))/titanium (Ti), a stack structureof aluminum (Al)/titanium (Ti)/indium zinc oxide (IZO)/titanium (Ti), ora stack structure of copper (Cu)/indium tin oxide (ITO)/copper oxide(Cu₂O).

That is, all of the detection electrode 80, the second low reflectionlayer 83, and the bridge 84 may function as a low reflection layer andmay have the same stack structure. Referring to FIG. 8, when all of thedetection electrode 80, the second low reflection layer 83, and thebridge 84 function as a low reflection layer, reflectance of externallight may be reduced in a portion other than the pixel area PA.

According to an embodiment, the upper layer 32 of the first lowreflection layer 30 and the second low reflection layer 83 may have thesame stack structure. A plurality of layers included in the upper layer32 may be the same as the plurality of layers included in the second lowreflection layer 83.

FIG. 9 is a plan view of a display apparatus, according to anotherexample embodiment. FIG. 10 is a cross-sectional view taken along a lineX-X′ of FIG. 9. Referring to FIGS. 9 and 10, unlike FIGS. 6 and 8, thebridge 84 may be below the second low reflection layer 83 and thedetection electrode 80.

The display apparatus including the above-described second lowreflection layer 83 may not need a separate black matrix layer and/or acircular polarizer in a non-pixel area for reflection of external light,and thus a thickness of the display apparatus may be reduced. Thus, afolding characteristic of the display apparatus may be improved. A WAD,in which a color of white light changes due to a color shift accordingto a viewing angle, may also be reduced.

A method of manufacturing the display apparatus will now be describedbelow.

FIGS. 11A through 11F are cross-sectional views for sequentiallydescribing a method of manufacturing the display apparatus, according toan example embodiment. The method of manufacturing the display apparatusaccording to an example embodiment may include sequentially forming aconductive layer 20′ and a low reflection layer 32′ above the substrate10, forming the first low reflection layer 30 including the lower layer31 having conductivity and the upper layer 32 above the lower layer 31,the pixel electrode 20, and the low reflection etching layer 32E abovethe pixel electrode 20 by patterning the conductive layer 20′ and thelow reflection layer 32′, forming the pixel-defining layer 40 above thefirst low reflection layer 30 and having the opening 40H exposing atleast a part of the low reflection etching layer 32E, exposing the pixelelectrode 20 by etching at least a part of the low reflection etchinglayer 32E by using the pixel-defining layer 40 as a mask, forming theintermediate layer 50 including an organic emission layer above theexposed pixel electrode 20, and forming the opposite electrode 60 abovethe intermediate layer 50.

Referring to FIG. 11A, after the thin film transistor TFT is formedabove the substrate 10, the conductive layer 20′ and the low reflectionlayer 32′ may be sequentially formed above the substrate 10. Theconductive layer 20′ and the low reflection layer 32′ may beelectrically connected to the thin film transistor TFT via a via hole12H.

According to an embodiment, an operation of stacking the low reflectionlayer 32′ may include an operation of sequentially stacking a pluralityof layers having different refractive indexes. As described withreference to FIGS. 3 and 4 above, refractive indexes and thicknesses ofthe plurality of layers may be determined such that lights incident fromoutside and reflected by the low reflection layer 32′ destructivelyinterfere with each other.

Referring to FIG. 11B, the conductive layer 20′ and the low reflectionlayer 32′ may be patterned. Through a patterning process, the pixelelectrode 20 and the lower layer 31 of the first low reflection layer 30spaced apart from the pixel electrode 20 may be formed in a portionelectrically connected to the thin film transistor TFT. Simultaneously,the lower reflection etching layer 32E and the upper layer 32 may berespectively formed above the pixel electrode 20 and the lower layer 31of the first low reflection layer 30. Thus, the first low reflectionlayer 30 including the lower layer 31 and the upper layer 32 may beformed.

The low reflection etching layer 32E and the upper layer 32 may includea plurality of layers having different refractive indexes. In thisregard, lights reflected from boundary surfaces of the plurality oflayers may destructively interfere with each other. Thus, the lowreflection etching layer 32E and the upper layer 32 may have lowreflectance and show a black color. The reflectance of the lowreflection etching layer 32E and the upper layer 32 may range from 0% toabout 6%.

Referring to FIG. 11C, the pixel-defining layer 40 having the opening40H exposing at least a part of the low reflection etching layer 32E maybe formed above the first low reflection layer 30. The pixel-defininglayer 40 may cover an edge of the low reflection etching layer 32E andexpose a central portion of the low reflection etching layer 32E.

Referring to FIG. 11D, the pixel electrode 20 may be exposed by etchingat least a part of the low reflection etching layer 32E by using thepixel-defining layer 40 as the mask. Since the pixel-defining layer 40originally covers the edge of the low reflection etching layer 32E, thelow reflection etching layer 32E covered by the pixel-defining layer 40may not be etched but may remain during an etching process. Thus, thelow reflection etching layer 32E may be above an edge of the pixelelectrode 20. Although not shown, the low reflection etching layer 32Emay be totally removed during the etching process.

Referring to FIG. 11E, after the pixel-defining layer 40 is formed andthe low reflection etching layer 32E is etched, the intermediate layer50 including the organic emission layer may be formed above the pixelelectrode 20, and then the opposite electrode 60 may be formed above theintermediate layer 50.

The intermediate layer 50 may be exposed by the pixel-defining layer 40and may include at least one common layer and the organic emissionlayer. The opposite electrode 60 above the intermediate layer 50 may beformed as one body over a plurality of pixels, unlike the pixelelectrode 20.

FIG. 11F is a cross-sectional view for describing an operation offorming the thin film encapsulation layer 70.

After the opposite electrode 60 is formed, the thin film encapsulationlayer 70 may be formed above the opposite electrode 60. The thin filmencapsulation layer 70 may prevent or reduce penetration of moisture oroxygen from outside into a display area.

The thin film encapsulation layer 70 may include the first inorganiclayer 71, the organic layer 72, and the second inorganic layer 73 thatare sequentially arranged above the opposite electrode 60. The firstinorganic layer 71 may include silicon oxide, silicon nitride, and/orsilicon oxynitride. The first inorganic layer 71 may be formed accordingto a structure therebelow, and thus, as shown in FIG. 11F, an uppersurface thereof may not be flat. The organic layer 72 may cover thefirst inorganic layer 71 and may form a flat upper surface. The organiclayer 72 may include one or more materials selected from the groupconsisting of polyethylene terephthalate, polyethylene naphthalate,polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene,polyarylate, and hexamethyldisiloxane. The second organic layer 73 maycover the organic layer 72 and may include silicon oxide, siliconnitride and/or silicon oxynitride.

According to the method of manufacturing the display apparatus describedabove, the pixel electrode 20, the lower layer 31, the upper layer 32,and the low reflection etching layer 32E may be formed by one mask,thereby increasing an effect of reflection of external light withoutincreasing a mask process. The method may not need to form a separateblack matrix layer and/or circular polarizer in a non-pixel area,thereby reducing a thickness of the display apparatus. A WAD, in which acolor of white light changes due to a color shift according to a viewingangle, may also be reduced.

FIGS. 12A through 12C are cross-sectional views for describing anoperation of forming the touch panel TP in an upper area of the thinfilm encapsulation layer 70 among a method of manufacturing the displayapparatus, according to another example embodiment.

According to an embodiment, the operation of forming the touch panel TPmay further include forming the detection electrode 80 detecting a touchsignal and including a plurality of conductive lines in a grid shape andthe second low reflection layer 83 surrounding the pixel electrode 20,forming the insulating layer 90 having the opening 90H exposing a partof the detection electrode 80 above the detection 80 and the second lowreflection layer 83, and forming the bridge 84 including a plurality ofconductive lines in a grid shape, filling the opening 90H of theinsulating layer 90, and electrically connected to the detectionelectrode 80 above the insulating layer 90.

Referring to FIG. 12A, after the thin film encapsulation layer 70 isformed, the detection electrode 80 including the plurality of conductivelines in the grid shape may be formed above the thin film encapsulationlayer 70 and the second low reflection layer 83 surrounding the pixelarea PA may be formed at the same layer as the detection electrode 80.The detection electrode 80 and the second low reflection layer 83 mayinclude the same material and may be simultaneously formed at the samelayer. The detection electrode 80 may detect a touch signal of a user ofthe display apparatus. The detection electrode 80 may include theplurality of first detection electrodes 81 of FIG. 5 and the pluralityof second detection electrodes 82 of FIG. 5, which cross each other.

Referring to FIG. 12B, the insulating layer 90 may be formed above thedetection electrode 80 and the second low reflection layer 83. Theinsulating layer 90 may have the opening 90H in an area overlapping thebridge 84 that will be formed later. The insulating layer 90 may have asingle layer structure or a multilayer structure including a transparentinorganic layer or organic layer. The inorganic layer may include one ofsilicon oxide (SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride(SiON), and oxide aluminum (AlO_(x)).

Referring to FIG. 12C, the bridge 84 overlapping a part of the detectionelectrode 80 on a plane and including a plurality of conductive lines ina grid shape may be formed above the insulating layer 90. The bridge 84may fill the opening 90H of the insulating layer 90 and may beelectrically connected to the detection electrode 80. The bridge 84 mayconnect, for example, the first detection electrodes 81 that are spacedapart from and neighboring each other to deliver an electrical signal inthe first direction D1 of FIG. 5.

According to an embodiment, an operation of forming the detectionelectrode 80 and the second low reflection layer 83 may include anoperation of sequentially stacking a plurality of layers havingdifferent refractive indexes. In this regard, lights reflected fromboundary surfaces of the plurality of layers included in the detectionelectrode 80 and the second low reflection layer 83 may destructivelyinterfere with each other.

According to an embodiment, an operation of forming the bridge 84 mayinclude an operation of sequentially stacking a plurality of layershaving different refractive indexes. In this regard, lights reflectedfrom boundary surfaces of the plurality of layers included in the bridge84 may destructively interfere with each other.

Referring to FIG. 10, a passivation layer 100 may be formed above thebridge 84. The passivation layer 100 may protect the detection electrode80. The passivation layer 100 may have a single layer structure or amultilayer structure including a transparent inorganic layer or organiclayer. The inorganic layer may include one of silicon oxide (SiO_(x)),silicon nitride (SiN_(x)), silicon oxynitride (SiON), and oxide aluminum(AlO_(x)).

According to the method of manufacturing the display apparatus describedabove, the detection electrode 80 and the second low reflection layer 83may be formed by one mask, thereby increasing an effect of reflection ofexternal light without an increase of a mask process. The method may notneed to form a separate black matrix layer and/or circular polarizer ina non-pixel area for reflection of external light, thereby reducing athickness of the display apparatus. Thus, a folding characteristic ofthe display apparatus may be improved. A WAD, in which a color of whitelight changes due to a color shift according to a viewing angle, mayalso be reduced.

As described above, according to the display apparatus and the method ofmanufacturing the display apparatus according to an embodiment of thepresent disclosure, a circular polarizer and/or a black matrix that areused to reflect external light may not be necessarily formed, and thus athickness of the display apparatus may be reduced, a foldingcharacteristic of the display apparatus may be enhanced, and a colorshift according to a viewing angle may be reduced. However, the scope ofthe present disclosure is not limited to the effect.

While one or more example embodiments have been described with referenceto the figures, it will be understood by one of ordinary skill in theart that various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A display apparatus comprising: a substrate; apixel electrode above the substrate; a first low reflection layer spacedapart from the pixel electrode at a same layer as the pixel electrodeand comprising a lower layer having conductivity and an upper layerabove the lower layer; a pixel-defining layer above the first lowreflection layer and having an opening exposing at least a part of thepixel electrode; an intermediate layer above the pixel electrode andcomprising an organic emission layer; and an opposite electrode abovethe intermediate layer, a low reflection etching layer between an edgeof the pixel electrode and the pixel-defining layer.
 2. The displayapparatus of claim 1, wherein a height of the first low reflection layeris greater than a height of the pixel electrode.
 3. The displayapparatus of claim 1, wherein the upper layer of the first lowreflection layer comprises a plurality of layers having differentrefractive indexes.
 4. The display apparatus of claim 3, wherein lightreflected from a boundary surface between the pixel-defining layer andan uppermost layer among the plurality of layers and light reflectedfrom a boundary surface between the plurality of layers destructivelyinterfere with each other.
 5. The display apparatus of claim 1, whereinthe reflectance of the upper layer of the first low reflection layer isless than about 6%.
 6. The display apparatus of claim 1, wherein the lowreflection etching layer is between the pixel-defining layer and theedge of the pixel electrode and the intermediate layer, wherein thepixel-defining layer overlaps the low reflection etching layer.
 7. Thedisplay apparatus of claim 1, wherein the upper layer of the first lowreflection layer comprises a stack structure of aluminum (Al)/aluminumoxide (AlOx)/titanium (Ti), a stack structure of aluminum (Al)/titanium(Ti)/indium zinc oxide (IZO)/titanium (Ti), or a stack structure ofcopper (Cu)/indium tin oxide (ITO)/copper oxide (Cu2O).
 8. The displayapparatus of claim 1, wherein the first low reflection layer iselectrically grounded.
 9. The display apparatus of claim 1, furthercomprising: a thin film encapsulation layer above the opposite electrodeand comprising at least one inorganic layer and at least one organiclayer; and a touch panel above the thin film encapsulation layer. 10.The display apparatus of claim 9, wherein the touch panel comprises: adetection electrode detecting a touch signal and comprising a pluralityof conductive lines in a grid shape; a second low reflection layerspaced apart from the detection electrode at a same layer as thedetection electrode and surrounding the pixel electrode; a bridgeoverlapping a part of the detection electrode on a plane, comprising aplurality of conductive lines in a grid shape, and electricallyconnected to the detection electrode; and an insulating layer betweenthe bridge and the detection electrode and having an opening throughwhich the bridge and the detection electrode are electrically connectedto each other.
 11. The display apparatus of claim 10, wherein widths ofthe plurality of conductive lines included in the detection electrodeare less than widths of the plurality of conductive lines included inthe bridge.
 12. The display apparatus of claim 10, wherein the detectionelectrode and the second low reflection layer comprise a plurality oflayers having refractive indexes, wherein lights reflected from boundarysurfaces of the plurality of layers destructively interfere with eachother.
 13. The display apparatus of claim 12, wherein the detectionelectrode and the second low reflection layer comprise a stack structureof aluminum (Al)/aluminum oxide (AlOx)/titanium (Ti), a stack structureof aluminum (Al)/titanium (Ti)/indium zinc oxide (IZO)/titanium (Ti), ora stack structure of copper (Cu)/indium tin oxide (ITO)/copper oxide(Cu2O).
 14. The display apparatus of claim 10, wherein the bridgecomprises a plurality of layers having refractive indexes, whereinlights reflected from boundary surfaces of the plurality of layersdestructively interfere with each other.